USB: Remove ZTE modem from unusual_devices

The ZTE modem entry causes usb-storage to ignore the device, but for some
versions of the device, usb-storage mode is required to get to modem ode. For
both kinds the tool: http://www.draisberghof.de/usb_modeswitch/

 should work.

Note that the various versions of the device have the same ProductId,
VendorId, and bcdDevice number, so we cannot have the entry for some and not
others.

Signed-off-by: Phil Dibowitz <phil@ipom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>